CVE-2026-32282 (GCVE-0-2026-32282)

Vulnerability from cvelistv5 – Published: 2026-04-08 01:06 – Updated: 2026-04-13 18:20
VLAI
Title
TOCTOU permits root escape on Linux via Root.Chmod in os in internal/syscall/unix
Summary
On Linux, if the target of Root.Chmod is replaced with a symlink while the chmod operation is in progress, Chmod can operate on the target of the symlink, even when the target lies outside the root. The Linux fchmodat syscall silently ignores the AT_SYMLINK_NOFOLLOW flag, which Root.Chmod uses to avoid symlink traversal. Root.Chmod checks its target before acting and returns an error if the target is a symlink lying outside the root, so the impact is limited to cases where the target is replaced with a symlink between the check and operation.
Severity
6.4 (Medium)
CVSS:3.1/AV:L/AC:H/PR:H/UI:N/S:U/C:H/I:H/A:H
SSVC
Exploitation: none Automatable: no Technical Impact: total
CISA Coordinator (v2.0.3)
CWE
  • CWE-61 - UNIX Symbolic Link (Symlink) Following
Assigner
Go
References
Impacted products
Vendor Product Version
Go standard library internal/syscall/unix Affected: 0 , < 1.25.9 (semver)
Affected: 1.26.0-0 , < 1.26.2 (semver)
Create a notification for this product.
Credits
Uuganbayar Lkhamsuren (https://github.com/uug4na)
Show details on NVD website
To clipboard 

{
  "containers": {
    "adp": [
      {
        "metrics": [
          {
            "cvssV3_1": {
              "attackComplexity": "HIGH",
              "attackVector": "LOCAL",
              "availabilityImpact": "HIGH",
              "baseScore": 6.4,
              "baseSeverity": "MEDIUM",
              "confidentialityImpact": "HIGH",
              "integrityImpact": "HIGH",
              "privilegesRequired": "HIGH",
              "scope": "UNCHANGED",
              "userInteraction": "NONE",
              "vectorString": "CVSS:3.1/AV:L/AC:H/PR:H/UI:N/S:U/C:H/I:H/A:H",
              "version": "3.1"
            }
          },
          {
            "other": {
              "content": {
                "id": "CVE-2026-32282",
                "options": [
                  {
                    "Exploitation": "none"
                  },
                  {
                    "Automatable": "no"
                  },
                  {
                    "Technical Impact": "total"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2026-04-13T17:47:42.666766Z",
                "version": "2.0.3"
              },
              "type": "ssvc"
            }
          }
        ],
        "providerMetadata": {
          "dateUpdated": "2026-04-13T18:20:56.456Z",
          "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
          "shortName": "CISA-ADP"
        },
        "title": "CISA ADP Vulnrichment"
      }
    ],
    "cna": {
      "affected": [
        {
          "collectionURL": "https://pkg.go.dev",
          "defaultStatus": "unaffected",
          "packageName": "internal/syscall/unix",
          "platforms": [
            "linux"
          ],
          "product": "internal/syscall/unix",
          "programRoutines": [
            {
              "name": "Fchmodat"
            }
          ],
          "vendor": "Go standard library",
          "versions": [
            {
              "lessThan": "1.25.9",
              "status": "affected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThan": "1.26.2",
              "status": "affected",
              "version": "1.26.0-0",
              "versionType": "semver"
            }
          ]
        }
      ],
      "credits": [
        {
          "lang": "en",
          "value": "Uuganbayar Lkhamsuren (https://github.com/uug4na)"
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "On Linux, if the target of Root.Chmod is replaced with a symlink while the chmod operation is in progress, Chmod can operate on the target of the symlink, even when the target lies outside the root. The Linux fchmodat syscall silently ignores the AT_SYMLINK_NOFOLLOW flag, which Root.Chmod uses to avoid symlink traversal. Root.Chmod checks its target before acting and returns an error if the target is a symlink lying outside the root, so the impact is limited to cases where the target is replaced with a symlink between the check and operation."
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "description": "CWE-61: UNIX Symbolic Link (Symlink) Following",
              "lang": "en"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-04-08T01:06:55.953Z",
        "orgId": "1bb62c36-49e3-4200-9d77-64a1400537cc",
        "shortName": "Go"
      },
      "references": [
        {
          "url": "https://go.dev/cl/763761"
        },
        {
          "url": "https://go.dev/issue/78293"
        },
        {
          "url": "https://groups.google.com/g/golang-announce/c/0uYbvbPZRWU"
        },
        {
          "url": "https://pkg.go.dev/vuln/GO-2026-4864"
        }
      ],
      "title": "TOCTOU permits root escape on Linux via Root.Chmod in os in internal/syscall/unix"
    }
  },
  "cveMetadata": {
    "assignerOrgId": "1bb62c36-49e3-4200-9d77-64a1400537cc",
    "assignerShortName": "Go",
    "cveId": "CVE-2026-32282",
    "datePublished": "2026-04-08T01:06:55.953Z",
    "dateReserved": "2026-03-11T16:38:46.556Z",
    "dateUpdated": "2026-04-13T18:20:56.456Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2",
  "vulnerability-lookup:meta": {
    "epss": {
      "cve": "CVE-2026-32282",
      "date": "2026-06-30",
      "epss": "0.00292",
      "percentile": "0.208"
    },
    "nvd": "{\"cve\":{\"id\":\"CVE-2026-32282\",\"sourceIdentifier\":\"security@golang.org\",\"published\":\"2026-04-08T02:16:03.467\",\"lastModified\":\"2026-06-17T10:35:29.120\",\"vulnStatus\":\"Analyzed\",\"cveTags\":[],\"descriptions\":[{\"lang\":\"en\",\"value\":\"On Linux, if the target of Root.Chmod is replaced with a symlink while the chmod operation is in progress, Chmod can operate on the target of the symlink, even when the target lies outside the root. The Linux fchmodat syscall silently ignores the AT_SYMLINK_NOFOLLOW flag, which Root.Chmod uses to avoid symlink traversal. Root.Chmod checks its target before acting and returns an error if the target is a symlink lying outside the root, so the impact is limited to cases where the target is replaced with a symlink between the check and operation.\"}],\"affected\":[{\"source\":\"security@golang.org\",\"affectedData\":[{\"vendor\":\"Go standard library\",\"product\":\"internal/syscall/unix\",\"defaultStatus\":\"unaffected\",\"collectionURL\":\"https://pkg.go.dev\",\"packageName\":\"internal/syscall/unix\",\"platforms\":[\"linux\"],\"programRoutines\":[{\"name\":\"Fchmodat\"}],\"versions\":[{\"version\":\"0\",\"lessThan\":\"1.25.9\",\"versionType\":\"semver\",\"status\":\"affected\"},{\"version\":\"1.26.0-0\",\"lessThan\":\"1.26.2\",\"versionType\":\"semver\",\"status\":\"affected\"}]}]}],\"metrics\":{\"cvssMetricV31\":[{\"source\":\"nvd@nist.gov\",\"type\":\"Primary\",\"cvssData\":{\"version\":\"3.1\",\"vectorString\":\"CVSS:3.1/AV:L/AC:H/PR:H/UI:N/S:U/C:H/I:H/A:H\",\"baseScore\":6.4,\"baseSeverity\":\"MEDIUM\",\"attackVector\":\"LOCAL\",\"attackComplexity\":\"HIGH\",\"privilegesRequired\":\"HIGH\",\"userInteraction\":\"NONE\",\"scope\":\"UNCHANGED\",\"confidentialityImpact\":\"HIGH\",\"integrityImpact\":\"HIGH\",\"availabilityImpact\":\"HIGH\"},\"exploitabilityScore\":0.5,\"impactScore\":5.9},{\"source\":\"134c704f-9b21-4f2e-91b3-4a467353bcc0\",\"type\":\"Secondary\",\"cvssData\":{\"version\":\"3.1\",\"vectorString\":\"CVSS:3.1/AV:L/AC:H/PR:H/UI:N/S:U/C:H/I:H/A:H\",\"baseScore\":6.4,\"baseSeverity\":\"MEDIUM\",\"attackVector\":\"LOCAL\",\"attackComplexity\":\"HIGH\",\"privilegesRequired\":\"HIGH\",\"userInteraction\":\"NONE\",\"scope\":\"UNCHANGED\",\"confidentialityImpact\":\"HIGH\",\"integrityImpact\":\"HIGH\",\"availabilityImpact\":\"HIGH\"},\"exploitabilityScore\":0.5,\"impactScore\":5.9}],\"ssvcV203\":[{\"source\":\"134c704f-9b21-4f2e-91b3-4a467353bcc0\",\"ssvcData\":{\"timestamp\":\"2026-04-13T17:47:42.666766Z\",\"id\":\"CVE-2026-32282\",\"options\":[{\"exploitation\":\"none\"},{\"automatable\":\"no\"},{\"technicalImpact\":\"total\"}],\"role\":\"CISA Coordinator\",\"version\":\"2.0.3\"}}]},\"weaknesses\":[{\"source\":\"nvd@nist.gov\",\"type\":\"Primary\",\"description\":[{\"lang\":\"en\",\"value\":\"CWE-59\"}]}],\"configurations\":[{\"nodes\":[{\"operator\":\"OR\",\"negate\":false,\"cpeMatch\":[{\"vulnerable\":true,\"criteria\":\"cpe:2.3:a:golang:go:*:*:*:*:*:*:*:*\",\"versionEndExcluding\":\"1.25.9\",\"matchCriteriaId\":\"C6C9C072-9817-402D-877F-F83584B07017\"},{\"vulnerable\":true,\"criteria\":\"cpe:2.3:a:golang:go:*:*:*:*:*:*:*:*\",\"versionStartIncluding\":\"1.26.0\",\"versionEndExcluding\":\"1.26.2\",\"matchCriteriaId\":\"39FE9BAF-55E9-43AA-B14E-239E7EF1D65D\"}]}]}],\"references\":[{\"url\":\"https://go.dev/cl/763761\",\"source\":\"security@golang.org\",\"tags\":[\"Patch\"]},{\"url\":\"https://go.dev/issue/78293\",\"source\":\"security@golang.org\",\"tags\":[\"Issue Tracking\"]},{\"url\":\"https://groups.google.com/g/golang-announce/c/0uYbvbPZRWU\",\"source\":\"security@golang.org\",\"tags\":[\"Mailing List\",\"Release Notes\"]},{\"url\":\"https://pkg.go.dev/vuln/GO-2026-4864\",\"source\":\"security@golang.org\",\"tags\":[\"Vendor Advisory\"]}]}}",
    "vulnrichment": {
      "containers": "{\"adp\": [{\"title\": \"CISA ADP Vulnrichment\", \"metrics\": [{\"cvssV3_1\": {\"scope\": \"UNCHANGED\", \"version\": \"3.1\", \"baseScore\": 6.4, \"attackVector\": \"LOCAL\", \"baseSeverity\": \"MEDIUM\", \"vectorString\": \"CVSS:3.1/AV:L/AC:H/PR:H/UI:N/S:U/C:H/I:H/A:H\", \"integrityImpact\": \"HIGH\", \"userInteraction\": \"NONE\", \"attackComplexity\": \"HIGH\", \"availabilityImpact\": \"HIGH\", \"privilegesRequired\": \"HIGH\", \"confidentialityImpact\": \"HIGH\"}}, {\"other\": {\"type\": \"ssvc\", \"content\": {\"id\": \"CVE-2026-32282\", \"role\": \"CISA Coordinator\", \"options\": [{\"Exploitation\": \"none\"}, {\"Automatable\": \"no\"}, {\"Technical Impact\": \"total\"}], \"version\": \"2.0.3\", \"timestamp\": \"2026-04-13T17:47:42.666766Z\"}}}], \"providerMetadata\": {\"orgId\": \"134c704f-9b21-4f2e-91b3-4a467353bcc0\", \"shortName\": \"CISA-ADP\", \"dateUpdated\": \"2026-04-13T17:47:38.773Z\"}}], \"cna\": {\"title\": \"TOCTOU permits root escape on Linux via Root.Chmod in os in internal/syscall/unix\", \"credits\": [{\"lang\": \"en\", \"value\": \"Uuganbayar Lkhamsuren (https://github.com/uug4na)\"}], \"affected\": [{\"vendor\": \"Go standard library\", \"product\": \"internal/syscall/unix\", \"versions\": [{\"status\": \"affected\", \"version\": \"0\", \"lessThan\": \"1.25.9\", \"versionType\": \"semver\"}, {\"status\": \"affected\", \"version\": \"1.26.0-0\", \"lessThan\": \"1.26.2\", \"versionType\": \"semver\"}], \"platforms\": [\"linux\"], \"packageName\": \"internal/syscall/unix\", \"collectionURL\": \"https://pkg.go.dev\", \"defaultStatus\": \"unaffected\", \"programRoutines\": [{\"name\": \"Fchmodat\"}]}], \"references\": [{\"url\": \"https://go.dev/cl/763761\"}, {\"url\": \"https://go.dev/issue/78293\"}, {\"url\": \"https://groups.google.com/g/golang-announce/c/0uYbvbPZRWU\"}, {\"url\": \"https://pkg.go.dev/vuln/GO-2026-4864\"}], \"descriptions\": [{\"lang\": \"en\", \"value\": \"On Linux, if the target of Root.Chmod is replaced with a symlink while the chmod operation is in progress, Chmod can operate on the target of the symlink, even when the target lies outside the root. The Linux fchmodat syscall silently ignores the AT_SYMLINK_NOFOLLOW flag, which Root.Chmod uses to avoid symlink traversal. Root.Chmod checks its target before acting and returns an error if the target is a symlink lying outside the root, so the impact is limited to cases where the target is replaced with a symlink between the check and operation.\"}], \"problemTypes\": [{\"descriptions\": [{\"lang\": \"en\", \"description\": \"CWE-61: UNIX Symbolic Link (Symlink) Following\"}]}], \"providerMetadata\": {\"orgId\": \"1bb62c36-49e3-4200-9d77-64a1400537cc\", \"shortName\": \"Go\", \"dateUpdated\": \"2026-04-08T01:06:55.953Z\"}}}",
      "cveMetadata": "{\"cveId\": \"CVE-2026-32282\", \"state\": \"PUBLISHED\", \"dateUpdated\": \"2026-04-13T18:20:56.456Z\", \"dateReserved\": \"2026-03-11T16:38:46.556Z\", \"assignerOrgId\": \"1bb62c36-49e3-4200-9d77-64a1400537cc\", \"datePublished\": \"2026-04-08T01:06:55.953Z\", \"assignerShortName\": \"Go\"}",
      "dataType": "CVE_RECORD",
      "dataVersion": "5.2"
    }
  }
}


Log in or create an account to share your comment.




Tags
Taxonomy of the tags.





Forecast uses a logistic model when the trend is rising, or an exponential decay model when the trend is falling. Fitted via linearized least squares.

Sightings

Author Source Type Date Other

Nomenclature

  • Seen: The vulnerability was mentioned, discussed, or observed by the user.
  • Confirmed: The vulnerability has been validated from an analyst's perspective.
  • Published Proof of Concept: A public proof of concept is available for this vulnerability.
  • Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
  • Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
  • Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
  • Not confirmed: The user expressed doubt about the validity of the vulnerability.
  • Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.


Detection rules are retrieved from Rulezet.